1. Field of the Invention
The present invention relates to a power supply for a liquid crystal display, and more particularly, to a power supply for a liquid crystal display using a light emitting diode for a backlight unit, the power supply integrating a DC power supply outside the liquid crystal display and a driving power supply inside the liquid crystal display to a single power supply.
2. Description of the Related Art
Among display devices, liquid crystal displays (LCDs) have recently been used for various kinds of products, such as desktop computers, laptop computers and AV equipment due to the fact that they have desirable features, such as small size, light weight and low power consumption.
These liquid crystal displays employ backlight units which emit the light necessary for pixels.
A backlight unit includes a plurality of bar lamps, a power circuit supplying power to the plurality of bar lamps and driving power to another circuit, and a controller receiving the driving power to control the levels of lamp luminance.
As for the above-described lamps, cold cathode fluorescent lamps (CCFLs) are generally used. However, in consideration of process rates, power consumption and life spans, backlight units using light emitting diodes (LEDs) as light sources have appeared.
However, a backlight unit having these light emitting diodes operates with a separate power supply by additionally using an external DC power supply, such as an adapter. The use of the external DC power supply may cause costs incurred for the provision of a power cable, a case and a printed circuit board (PCB) forming an adapter, reduce the mobility of liquid crystal displays and harm the appearance of liquid crystal displays.